ISS 'nauts take to the escape pods in Russian sat-prang debris peril

'Nauts crewing the International Space Station were forced to take to the escape capsules over the weekend, as a chunk of wreckage from a mysterious satellite collision in 2009 hurtled towards the orbiting outpost.

Fortunately as it turned out the speeding fragment passed by more than 11km from the station. Normally the ISS would have been moved out of its way using manoeuvring thrust, but the fragment was newly spotted by Earth-based tracking networks and there was insufficient lead time to execute such an operation.

In accordance with pre-planned drills, the six astronauts and cosmonauts aboard the station got into the two Soyuz capsules docked to the ISS, three getting into each. In the event of the station suffering catastrophic damage from a debris strike, the two trios could then have reached Earth safely, though fortunately no such disaster occurred on this occasion. It was the third time that a station crew has had to carry out escape-podule drills in earnest.

According to NASA:

A small piece of Cosmos 2251 satellite debris safely passed by the International Space Station at 2:38a.m. EDT, Saturday March 24 allowing the six Expedition 30 crew members onboard the orbiting complex to exit their Soyuz spacecraft and resume normal activities.

Cosmos 2251 – a defunct military communications satellite launched in 1993 – crashed into an up-and-running Iridium bird above northern Russia in 2009. The Iridium constellation was originally intended to be the world's first global mobile phone network, but as things turned out international GSM roaming robbed it of its main customer base.

Iridium duly went bankrupt, but was then reborn with US government backing: it remains one of only a few solutions offering truly worldwide voice and data (albeit very limited bandwidth) without requiring a cumbersome directional dish. As such it is often used in military and intelligence applications – for instance certain kinds of tracking bugs, communications with submerged submarines etc etc – perhaps offering a clue as to why the US authorities were keen to see it saved.

The 2009 collision was thought to result in only brief, local network outages for the Iridium system and full coverage was restored swiftly. The resulting wreckage pushed up overall space debris levels in near-Earth space by around 3 per cent. Initially the debris cloud was not dangerous to the ISS, but as time has gone by some of the fragments have descended to the same orbital level as the station.

Naturally the 2009 prang gave rise to many conspiracy theories suggesting that the Russians had purposely taken out the Iridium bird to prevent a certain message or messages getting though. Nobody has ever managed to stand up such a story, however. ®